1. Field of the Invention
This invention relates generally to vehicle airbags, and more particularly to an airbag seat release safety system that allows the front seat of the vehicle and/or backrest of the seat to move upon deployment of the airbag.
2. Brief Description of the Prior Art
Vehicle airbags are supplemental restraint systems that inflate very rapidly upon the vehicle being involved in a collision of sufficient magnitude to provide a cushion between the occupant and the steering wheel and interior surfaces of the vehicle. The driver's side bag is mounted in the steering wheel and the passenger bag is mounted on the dashboard on the passenger side of the vehicle.
When the vehicle is involved in a frontal collision at a speed of from about 12-15 mph, the sudden deceleration of the vehicle causes two crash sensors to send an electrical signal to a diagnostic module that self tests to confirm that a crash event is taking place and, if such is confirmed, then allows the signal to trigger the airbag deployment. All of this takes place in about 30 milliseconds, and the entire inflation/deflation cycle takes place in less than 1/2 second. The speed of the airbag inflating is about 200 mph. The airbag deployment force is greatest in the first 2-3 inches after the airbag begins to inflate and the force decreases as the airbag inflates farther.
Although the airbag is effective in saving many lives, many people receive bruises, cuts, abrasions, broken bones, and serious injuries, and some people are even killed, due to the explosive inflation of the airbag itself. Most serious airbag inflation injuries are caused because the occupant was too close to the airbag when it started to deploy due to the distance between the occupant and the steering wheel or dashboard when the vehicle is being driven. The front seat of the vehicle is normally fixed in the vehicle to prevent movement, thus when a crash occurs, the occupant is thrown violently forward as the airbag begins to inflate with explosive force.
There are several patents that disclose various seat release mechanisms and airbag systems.
Husted, U.S. Pat. No. 5,813,726 discloses an inertia locking device for a mechanical seat fore and aft and backrest adjuster mechanism which automatically locks the seat adjustment mechanism to prevent movment of the seat and backrest in the event of a vehicle collision.
Barnes et al, U.S. Pat. No. 5,803,491 discloses a disabling system for an inflatable airbag restraint system that automatically disables deployment of the airbag when the seat is moved forward of a predetermined seat position and enables deployment of the airbag when the seat is moved rearward of the predetermined seat position.
Fujita et al, U.S. Pat. No. 5,074,583 discloses an airbag system for vehicles including a seating condition sensor that detects the seating condition of a passenger, the seat position, reclining angle, passenger size, and posture, and a control unit that controls the operation of the airbag in accordance with the seating condition of the passenger so that the inflated airbag is brought into optimal contact with the passenger.
The present invention is distinguished over the prior art in general, and these patents in particular by an airbag seat release system that releases the front seat mounted in a vehicle to move upon deployment of an airbag in the vehicle. The release system includes an actuator connected with a latch mechanism on the seat assembly powered by an electrical signal supplied by the airbag deployment circuit. The latch mechanism is movable between a normally latched position preventing movement of the seat and a released position allowing movement of the seat relative to the vehicle. Upon deployment of the airbag, the actuator is activated responsive to the electrical signal to move the latch to the released position allowing the seat to move relative to the vehicle as the airbag is deployed. A ram connected with the seat assembly simultaneously propels the seat rearward. A stop member controls the extent of movement of the seat and backrest. The release system may have a latch connected with the seat mounting rails to enable the seat and backrest to slide as a unit in the released position, a latch connected between the seat and backrest to enable the backrest to pivot relative to the seat in the released position, or may have both a latch connected with the seat mounting rails and a latch connected between the seat and the backrest to enable the seat to slide as a unit and the backrest to pivot relative to the seat in the released position.